金属材料表面及内部的裂纹扩展是引起金属构件断裂失效的主要原因之一, 裂纹研究一直是金属材料领域的重点内容。某轨道车辆抗侧滚扭杆轴在生产过程中出现了裂纹, 采用宏观检验、化学成分分析、力学性能测试、金相检验的方法, 对扭杆轴的裂纹成因进行了分析。结果表明: 扭杆轴裂纹是淬火处理造成的, 在后续的矫直工序中又产生了二次裂纹。最后, 针对扭杆轴裂纹产生的原因提出了预防和改进措施。

The propagation of surface and internal cracks of metals is one of the main reasons to cause the fracture failure of metal structural parts. The research on cracks has been an important content in the field of metal materials. Crack occurred to an anti-rolling bar shaft of the railway vehicle during the production process. The causes of cracks of the anti-rolling bar shaft were analyzed by the methods of macrographic examination, chemical composition analysis, mechanical property testing and metallographic examination. The results show that: cracks of the anti-rolling bar shaft were caused by quenching treatment, and the following straightening process induced the secondary cracks in addition. Finally, preventive and improving measures were put forward according to the causes of cracks of the anti-rolling bar shaft.